Jose Aguinaga on Passkeys, MPC, and AA Wallets

Sep 22, 2023

In this episode, Jose Aguinaga, Head of Digital Custody Services at SEBA Bank in Switzerland, discusses topics such as elliptic curve cryptography, passkeys, homomorphic encryption, distributed key generation, and account abstraction smart wallets. They explore the differences between passkeys and ECDSA, the challenges of using passkeys in blockchain authentication, and the applications of multi-party computation (MPC) in protecting private information and collaboration. The episode also covers the concept of distributed key generation (DKG) and its application in signing data, as well as the permissions architecture and challenges in limiting access to transactions.

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Introduction

00:00 • 2min

Exploring the Blockchain Ecosystem and PASKI

02:13 • 18min

Passkeys and Web Authentication

19:58 • 8min

Differences between Passkeys and ECDSA

28:17 • 23min

Passkeys and Authentication in Blockchain

51:29 • 24min

DER vs CBOR Formats and Signature Processing

01:15:38 • 4min

Past Keys and Multi-Party Computation

01:20:03 • 5min

Distributed Key Generation (DKG) and its Application in Multi-Party Computation (MPC) and Signing Data

01:25:20 • 25min

Discussion on Capsule, exiting the key, and Dragon Ball references

01:50:09 • 1min

Permissions Architecture and Challenges in Limiting Access to Transactions

01:51:23 • 5min

MPC Solutions in Cheaper Blockchain Contexts

01:56:23 • 4min

Halo 2 Demo and ZK Technology

02:00:29 • 5min

Concluding the Conversation on Passkeys and Future Resources

02:05:46 • 3min

My guest today is Jose Aguinaga. Jose is Head of Digital Custody Services at SEBA Bank in Switzerland. He was previously Head of Engineering at HOPR.

Jose is also the creator of passkeys.is and mpc.is, two valuable educational resources that describe and demonstrate passkeys and multi-party computation, respectively.

On this episode, Jose and I go deep on elliptic curve cryptography, ECDSA, passkeys, homomorphic encryption, distributed key generation, account abstraction smart wallets and much more.

If you're interested in the frontier of self custody smart wallet user experience, this episode is for you.

It was a pleasure talking to Jose who is knowledgable, humble, and generous. I hope you enjoy the show.

As always, this show is provided as entertainment and does not constitute legal, financial, or tax advice or any form of endorsement or suggestion. Crypto has risks and you alone are responsible for doing your research and making your own decisions.

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(00:00:00) Intro (00:01:18) Interview start (00:02:27) Jose’s cryptography origin story (00:09:15) What is Elliptic curve cryptography? (00:13:45) What is ECDSA? (00:20:20) What are Passkeys? (00:25:10) What is WebAuthn? (00:28:35) Passkeys (secp256r1) vs EOAs (secp256k1) (00:31:30) Is the secp256r1 compromised? (00:39:50) What happens when creating a passkey? (00:43:55) Passkey UX gotchas & cloud keychain sync (00:53:45) Advantages of passkeys (00:57:15) Passkeys as Smart Wallet signers (01:01:00) Hierarchical deterministic passkeys? (01:03:25) Cross-origin passkeys (01:11:20) Public key registries (01:13:14) largeBlob in Safari 17 (01:15:40) Understanding passkey signatures in DER and CBOR formats (01:20:10) p-384 support (01:21:30) MPC: Multi-party computation, homomorphism, Paillier cryptosystems (01:25:40) DKG: Distributed key generation (01:29:30) Signing an intent with an MPC DKG (01:32:20) Threshold signature scheme (01:35:00) Silence Labs' Decompute MPC for blockchain applications conference (01:37:15) MPC signing vs smart contract passkey signature verification for Account Abstraction applications (01:39:40) Lit Protocol (01:44:40) MPC based AA permissions (01:48:40) Risks of MPC based smart wallet signing: censorship (01:51:20) AA Permissions UX (02:00:28) Know Nothing Labs' Halo2 (zk) based signing (02:04:30) ZKSync's native 4337 (02:05:52) Outro